The field of art to which this invention pertains is the reduction of the temperature in the regeneration zone of a fluid catalytic cracking process. More specifically, the invention relates to reducing the maximum temperature reached in the regeneration zone of a fluid catalytic cracking process without reducing the amount of coke burned therein by simultaneously circulating, in admixture with cracking catalyst, fluidizable low coke make solid particles which have a surface area of less than about 5 m.sup.2 /g and which low coke make solid particles generate less than about 0.2 weight percent coke on the spent low coke make solid particles in the ASTM standard method for testing fluid cracking catalyst by microactivity test (MAT) in an amount sufficient to result in a ratio of low coke make solid particles to cracking catalyst from about 1:100 to about 10:1, thereby lowering the regenerator temperature from about 10.degree. F. to about 250.degree. while simultaneously not affecting the operation of the reaction zone.